Answer:
The work done to get you safely away from the test is 2.47 X 10⁴ J.
Explanation:
Given;
length of the rope, L = 70 ft
mass per unit length of the rope, μ = 2 lb/ft
your mass, W = 120 lbs
mass of the 70 ft rope = 2 lb/ft x 70 ft
= 140 lbs.
Total mass to be pulled to the helicopter, M = 120 lbs + 140 lbs
= 260 lbs
The work done is calculated from work-energy theorem as follows;
W = Mgh
where;
g is acceleration due gravity = 32.17 ft/s²
h is height the total mass is raised = length of the rope = 70 ft
W = 260 Lb x 32.17 ft/s² x 70 ft
W = 585494 lb.ft²/s²
1 lb.ft²/s² = 0.0421 J
W = 585494 lb.ft²/s² = 2.47 X 10⁴ J.
Therefore, the work done to get you safely away from the test is 2.47 X 10⁴ J.
PLZ HELP ILL GIVE RBAINLIEST
Which of the following factors can affect the strength of electric or magnetic fields? (YOU MAY SELECT MORE THAN ONE ANSWER)
Strength of the magnet/electric charge
The material that is creating the field
The mass of the object creating the field
The distance from the source of the field
Which is TRUE about static electricity?
It is a stationary electric charge that builds up on an insulating material and is discharged when another material touches it.
It can flow from an electric outlet along a wire to a lamp.
It travels in a circuit.
It usually has a switch that allows you to turn something on or off.
plssssssssssssss answer correct pls correct answers only plsssss not in a mean way
Answer:
the first one stationary charge
first oneeeeeeeeeeeeeeeeeeee
Gaseous sulfur dioxide is a compound that combines with water in the atmosphere to form acid rain. What is the primary source of sulfur dioxide?
O volcanic emissions
O combustion of fossil fuels
O destruction of tropical forests
O mining and mineral extraction
Which bond(s) shown are double bonds?
Answer:
in the diagram shown, Oxygen is the only one that has a double bond.
Explanation:
Chemical bonds are the way that electors are shared between atoms to form molecules whose energy is less than the energy of individual atoms.
A graphical way to show these electrons is to represent them by point in the atoms. Every other point represents a shared bond or pair of electrons.
Therefore for simple bonds two electrons are drawn. For double bonds four electrons and for triple bonds six electrons.
Therefore, in the diagram shown, Oxygen is the only one that has a double bond.
A car of mass 1800 kg can be just be lifted. What is the least force that the electromagnet must use to lift the car? (1 g = 10 N/kg)
Answer:
f=a×mm=1800kg
1800000g×10N/kg
18000000N force is required to life the car
Changes of
Which now represents the change of state described
above?
M
ham shows changes of state between solid.
se atoms of a substance lase energy
Bacharest Betore the change, the atoms
ether but are able to slide past one another
Answer:b yuh
Explanation:
Yuh
Energy is radiated or transmitted in the form of rays or waves or particles.
B. radiation
C. convection
D. conduction
Answer:
B radiation
Explanation:
every type of transmitted waves are radioactive in a way.
Two resistors R1 = 3 Ω and R2 = 6 Ω are connected in parallel. What is the net resistance in the circuit?
Answer:
"2Ω" is the net resistance in the circuit.
Explanation:
The given resistors are:
R1 = 3Ω
R2 = 6Ω
The net resistance will be:
⇒ [tex]\frac{1}{R_{net}} =\frac{1}{R_1} +\frac{1}{R_2}[/tex]
On substituting the values, we get
⇒ [tex]\frac{1}{R_{net}} =\frac{1}{3} +\frac{1}{6}[/tex]
On taking L.C.M, we get
⇒ [tex]\frac{1}{R_{net}} =\frac{2+1}{6}[/tex]
⇒ [tex]\frac{1}{R_{net}} =\frac{3}{6}[/tex]
⇒ [tex]\frac{1}{R_{net}} =\frac{1}{2}[/tex]
On applying cross-multiplication, we get
⇒ [tex]R_{net}=2 \Omega[/tex]
given that two vectors A=i,2j-2k and B=6i+3j+2k find A +B
Answer:
7i, 5j, 0k
Explanation:
Add up the two vectors.
Add
i+i 1+6 = 7i
j+j 2+3 = 5j
k+k -2+2 = 0k
therefore A+B = (7i, 5j, 0k)
How much heat does it lose to change 126 g of water from 67°C to 37°C?
Explanation:
convert gram into kg q means amount of heat lost
who compose the Ghana national anthem
Answer:
Philip Gbeho
Explanation:
Suppose that 2 J of work is needed to stretch a spring from its natural length of 24 cm to a length of 42 cm. (a) How much work is needed to stretch the spring from 32 cm to 34 cm
Answer:
Workdone = 0.025 Joules
Explanation:
Given the following data;
Workdone = 2J
Extension = 42 - 24 = 18 cm to meters = 18/100 = 0.18m
The workdone to stretch a string is given by the formula;
Workdone = ½ke²
Where;
k is the constant of elasticity.
e is the extension of the string.
We would solve for string constant, k;
2 = ½*k*0.18²
2 = ½*k*0.0324
Cross-multiplying, we have;
4 = 0.0324k
k = 4/0.0324
k = 123.46 N/m
a. To find the workdone when e = 32, 34.
Extension = 34 - 32 = 2 to meters = 2/100 = 0.02m
Workdone = ½*123.46*0.02²
Workdone = 61.73 * 0.0004
Workdone = 0.025 Joules
Therefore, the amount of work (in J) needed to stretch the spring from 32 cm to 34 cm is 0.67.
What is Na2SO4?
Help pleaseeee.
Please please help I'm stuck!!!
Answer: iDc im in 3grade
Explanation:sorry
Which types of reactions are also redox reactions?
Answer:
Your ans is B)
Explanation:
Hope its right
if wrong firgive me
Two resistors R1 = 3 Ω and R2 = 6 Ω are connected in parallel. What is the net resistance in the circuit?
Answer:
2ohms
Explanation:
the net resistance is given by
1/R=1/R1 +1/R2,we are supposed to find R
thus by making R the subject ....
R=R1•R2/R1+R2
R=3•6/3+6
R=18/9 =2Ohms
strong bases are good conductors of
Answer:
Electricity ⚡️
Explanation:
Three 5 Ohm resistors are connected in parallel to a 9 Volt power supply. What is the current through each resistor?
Answer:
I₁ = I₂ = I₃ = 12 A
Explanation:
Since the resistors are connected in parallel across a battery. Hence, the voltage across each of them will be the same, which will be equal to the voltage of the power supply. Since each resistor has the same resistance of 5 Ω. Therefore. the current across each resistor will also be the same. We can easily calculate these current values by the use of Ohm's Law, as follows:
[tex]V = IR\\I_{1}=I_{2}=I_{3}=\frac{V}{R} \\\\I_{1}=I_{2}=I_{3}=\frac{9\ Volt}{5 \Omega}\\\\[/tex]
I₁ = I₂ = I₃ = 12 A
two masses are attached by a light string and looped over two frictionless pulleys. object 1 has mass 200g and accelerates upwards at the rate of 4.90m/s^2. determine the mass of object 2
Answer:
F=ma
F=10(mass of object 2-0.2)
F=ma
=0.2×4.9
=0.98N
10x-2=0.98(assume that mass of second object is X)
10x =0.98+2
10x=2.98
X=0.298kg
the mass of second object=298g
t
PLEASE HELP ME WITH ONE QUESTION
If 1000 J of heat energy is lost from a piece of hot metal which is placed into a cup of cool water, how much energy is gained by the water?
Answer:
1000J
Explanation:
According to the law of calorimetry;
Heat lost by cold substance = Heat gained by hot substance
If 1000 J of heat energy is lost from a piece of hot metal,
heat lost by hot substance = 1000J
Since we are to determine how much energy is gained by the water, using the law
Heat lost by hot metal = heat gained by the water
Hence heat gained by the water = 1000J
TOINETS
Assuming that distances are
equal, which of the following
objects would have the MOST
gravitational force with you?
A. Jupiter
NETTUNE
B. Earth
UNIVERSE
C. Sun
Answer:
The sun.
Explanation:
The sun has the most gravitational pull.
how are characteristics of electromagnetic waves affected by medium
Hello,
QUESTION)Light is an electromagnetic wave, its speed is maximum in space and almost in the air where interactions have almost no effect. In other non-opaque media, light is subject to several phenomena: refraction and reflection. Part of the incident ray will be reflected in the same medium while the other part will be refracted in the new medium with a lower speed. In general, the medium influences the speed, and therefore the wavelength.
help, it's an emergency !!!!!!!
A) how many cm³ are there in 0.08L?
B) How many dm³ are there in 750mL?
Answer:
A) 80 cm³
B) 0.75 dm³
Explanation:
I hope this help❤️
PLZ HELP PLZ ILL GIVE BRAINLIEST TO BEST ANSWERED
The Earth's gravity pulling on a skydiver: Contact or Non Contact
Friction from a car's brakes causing it to stop: Contact or Non Contact
The repulsive magnetic force between the north poles of two magnets: Contact or Non Contact
The attractive electrostatic force between an electrically charged balloon and a wall: Contact or Non Contact
Answer:
1.Contact because its a contact force
2 Contact because when the car is stopping it is coming in to contact with the ground.
3 non Contact because magnets don't need to have contact they pull
4 non Contact because its not a contact force
Can light have inertia??
Answer:
Yes.
Explanation:
Yes Light has inertia, since inertia is in units of mass.
Please help
A 90 kg football player is running at 0.9 m/s. Assuming a head on collision, at what speed would a 110 kg football player have to run into the 90 kg
player in order to stop him
Answer:
The two moments must be the same:
p1=p2
m1v1=m2v2
v2=(m1v1)/m2
v2=(90 kg x 0.9 m/s)/110kg=0.7 m/s
A projectile is thrown with a velocity of 40 m/s, 45 degrees above the +x-axis. Determine its initial x-velocity and its initial y-velocity.
x-component is V·cos(angle)
y-component is V·sin(angle)
When the angle is 45°, its sin and cos are both 1/2·√2 .
Vx = 20·√2 = 28.28 m/s
Vy = 20·√2 = 28.28 m/s
The human body stores chemical energy from digested food. Some of the chemical energy is converted into mechanical energy when the body moves. Which statement is best supported by this information?
The body does not convert chemical energy to thermal energy.
The body does not convert chemical energy to kinetic energy.
Digested food is a source of potential energy.
Digested food is a form of radiant energy.
Answer:
Your answer is c :)
Explanation:
The desperate contestants on a TV survival show are very hungry. The only food they can see is some fruit hanging on a branch high in a tree. Fortunately, they have a spring they can use to launch a rock. The spring constant is 900 N/m, and they can compress the spring a maximum of 45 cm. All the rocks on the island seem to have a mass of 500 g.
a) With what speed does the rock leave the spring?
b) To what height can the rock be launched?
Answer:
a) v = 18.86 m / s, b) h = 8.85 m
Explanation:
a) For this exercise we can use the conservation of energy relations.
Starting point. Like the compressed spring
Em₀ = K_e + U = ½ k x² + m g x
the zero of the datum is placed at the point of the uncompressed spring
Final point. With the spring if compress
Em_f = K = ½ m v²
how energy is conserved
Em₀ = Em_f
½ k x² + m g x = ½ m v²
v² = [tex]\frac{k}{m}[/tex] x² + 2gx
let's reduce the magnitudes to the SI system
m = 500 g = 0.500 kg
x = -45 cm = -0.45 m
the negative sign is because the distance in below zero of the reference frame
let's calculate
v² = [tex]\frac{900}{0.500}[/tex] 0.45² + 2 9.8 (- 0.45)
v = √355.68
v = 18.86 m / s
b) For this part we use the conservation of energy with the same initial point and as an end point at the point where the rock stops
Em_f = U = m g h
Em₀ = Em_f
½ k x²2 + m g x = m g h
h = ½ [tex]\frac{k}{g}[/tex] x² + x
let's calculate
h = [tex]\frac{1}{2} \ \frac{900}{9.8 } \ 0.45^2[/tex] - 0.45
h = 8.85 m
measured from the point where the spring is uncompressed